SiteStream is an AS3 library for parsing XML into first-class objects, read a basic tutorial here.

SiteStream aims to solve certain inflexibilities of AS3. It is not a replacement for flashvars or Remoting/AJAX. It is better to consider it a non-compiled part of your application.

Consider these traits of AS3/Flash Player:

• AS3 is strongly typed and pre-compiled, meaning that code dependancies will automatically get bundled together without special provisions to split them into seperate SWFs (like Flash Builder's 'Module's).
• The Flash Player offers no control over the order in which parts of a SWF are loaded (I have a feeling they do this for server compatibility reasons).
• Which of these SWFs to load, and in what order, enerally depends on which parts of your app the user visits.

These SWFs quickly become unmanagable, SiteStream provides a simple way of loading the appropriate SWF at the appropriate time.

The XML files themselves are also only loaded when needed by the app.

Whilst AS3 (and other C-based languages) are great for fine functional programming, XML based languages have long been recognised as stronger in broader architectural programming situations (e.g. MXML, XAML, etc). SiteStream allows the core displays, data-sources and visual assets of your app to be configured and assembled in XML.

The benefits of doing this in a non-compiled format (as opposed to MXML):

• Implicit management of SWF loading.
• Easily switch from XML files to dynamically generated XML output (from any number of existing CMSs).

After saying all of this, SiteStream doesn't impose any rules upon it's use in your applications, and if you want to use it purely for the loading of data structures you're perfectly free to do so.